Objective To investigate the prevalence of kidney damage and risk factors in residents older than 40 years in Beijing， one of the greatest Chinese metropolis. 

Methods Two thousand three hundred and fifty-three residents from four of eight communities in one district of Beijing were interviewed and tested for albuminuria-morning spot urine albumin to creatinine ratio (abnormal:≥30 mg/g)， reduced renal function-estimated glomerular filtration rate by abbreviated MDRD equation [abnomal: < 60 ml▪min^-1▪(1.73 m²)^-1]， hematuria and pyuria-morning spot urine dipstick confirmed by urine microscopy. The associations among demographic characteristics， health characteristics (eg. smoking， diabetes， and hypertension) and indicators of kidney damage were examined. 

Results Albuminuria was detected in 6.2% of subjects， reduced renal function in 3.0%， hematuria in 0.8%， and non-infective pyuria in 0.09%. Approximately 9.4% of subjects had at least one indicator of kidney damage. Diabetes and systolic blood pressure were independently associated with albuminuria. Hyperuricemia， albuminuria， age， hypercholesteremia and gender were independently associated with reduced renal function. 

Conclusion The prevalence and risk factors of CKD in population older than 40 years in a Chinese metropolis are similar to those of developed countries.

Objective To investigate the effect of losartan on urinary podocyte excretion in diabetic nephropathy (DN) patients. Methods After 6-week washout， thirty type 2 diabetic nephropathy patients received 50 mg/d losartan for 8 weeks followed by 100 mg/d losartan for an additional 8 weeks. Ten healthy volunteers served as control. Podocytes were identified and quantitated by immunofluorescence staining of urinary sediments labeled by monoclonal antibody podocalyxin. Results Urinary detached podocytes was absent in healthy controls. The amount of podocytes in the urine of DN patients were significantly greater than normal control. Therapy with losartan significantly decreased urinary podocyte excretion in DN patients. But no statistical difference of urinary podocyte amount was seen between different dose therapy phases. There was no significant correlation of the amount of urinary podocytes with urinary protein excretion and systemic blood pressure. In addition， there was significant difference of podocyte excretion between CKD stage 2 and 3 patients before therapy. Losartan treatment significantly decreased the urinary podocyte excretion of DN CKD stage 2 patients， whereas no changes were observed in CKD stage 3 DN patients. Conclusions In diabetic nephropathy， urinary podocyte is suggested to be early effective marker of disease progression. Losartan may be effective to prevent podocyte injury in DN.

Objective To prospectively study the early diagnosis value of cystatin C in acute renal failure (ARF). Methods One hundred and three critically ill patients hospitalized in intensive care unit were enrolled in the study and blood samples were collected daily. Serum creatinine (Scr) and cystatin C were detected by enzymic method and particle-enhanced turbidimetric immunoassay (PETIA)， respectively. Glomerular filtration rate (GFR) was estimated by Cockroft-Gault equation. ARF was diagnosed by RIFLE criteria of ADQI (R: Scr increased by ≥50%，I: Scr increased by ≥100%， F: Scr increased by ≥200%， L: Loss of kidney function， E:ESRD). Simultaneously， ARF was detected when cystatin C increased by ≥50%， ≥100%， ≥200%. Results Twenty-seven patients(26.2%) developed ARF at different degree， the other 76 cases without ARF were served as control group. During the following up of 27 ARF patients，15 cases experienced R criteria，18 cases experienced I criteria， 9 cases experienced R criteria and 3 cases experienced IE criteria. Cystatin C in 27 ARF patients was dramatically increased as compared to that of control group(P < 0.01). Significant linear correlation was found between cystatin C and Scr (r=0.747， P < 0.01)， [cystatin C]-1 and estimated GFR(R=0.815， P < 0.01). Diagnostic medium time of ARF by cystatin C and Scr was as following: R criteria of 15 patients 2 days(range 1~4 days)and 3 days(range 2~6 days)(P=0.011)， I criteria of 18 patients 4 days(range 1~8 days)and 5.5 days(range 2~10 days)(P=0.006)， F criteria of 5 days(range 3~11 days)and 6 days(range 3~13 days)(P=0.02)， respectively. ROC analysis confirmed diagnostic accuracy for Cystatin C in ARF， area covered under the AUC curve was 0.995 (95% confidence interval:0.984~1.006)(P<0.001). With the cut-off value of Cystatin C increased ≥50%，the diagnostic sensitivity and specificity in ARF were 93% and 96%， respectively. Conclusions Serum cystatin C is superior to serum creatinine as a predictive marker of ARF in an early stage. Cystatin C can be one of the early detection markers of ARF.

Objective To investigate the expression of osteoprotegerin(OPG)and osteoprotegerin ligand (RANKL) in high turnover renal bone disease and study the correlation between immunohistochemistry and histomorphometric measurements of bone. Methods Bone biopsy was performed on ten chronic renal failure (CRF) patients and three normal persons. Bone tissues were studied for OPG and RANKL expression by immunohistochemistry and histomorphometric measurement using an automatic image analysis system. Results Ten uremic patients were found to have high turnover bone disease according to the bone histology. A significantly increasing tendency of RANKL-positive cells and a significantly reducing tendency of OPG-positive cells were observed in CRF patients compared with control subjects. Histomorphometric analysis showing that the number of RANKL-positive cells was significantly correlated with histologically increasing bone resorbtion (both bone resorbtion surface and number of osteoclasts) in uremic patients. Conclusion OPG/RANKL/RANK system is involved in high turnover renal bone disease by parathyroid hormone.

Objective To evaluate the association between the C242T and A640G polymorphism in the p22phox gene， an essential component of NADPH oxidase， and type 2 diabetic nephropathy patients in Shanghai. Methods C242T and A640G polymorphism of the p22phox gene were detected by polymerase chain reaction-restriction fragment-length polymorphism in 194 type 2 diabetic patients，including 71 diabetic nephropathy， and 105 healthy subjects. Meanwhile the fast blood glucose， fast blood insulin， blood pressure， TG， TC， HDL， LDL， HbA1c and body mass index were examined. Results The frequency of CT+TT genotype in diabetic nephropathy patients was significantly higher than that in type 2 diabetic subjects and healthy subjects (26.76% vs. 17.07%，3.81%，P=0.0002)； and so was the T allele genotype (22.54% vs. 13.42%，2.86%，P=0.0001). There were no differences of the AG+AA genotypes or A allele genotypes among three groups(P > 0.05). Logistic multiple regression analysis showed T242 allele， body mass index， fasting blood glucose， HbA1c， Homa-IS， systolic blood pressure were risk factors of type 2 diabetic nephropathy. Conclusions p22phox C242T gene polymorphism is associated with diabetic nephropathy in Shanghai people. p22phox subunit T allele mutation is probabaly one of predisposing genes of type 2 diabetic nephropathy， and p22phox A640G gene polymorphism is not associated with diabetic nephropathy in Shanghai people. T242 allele， fasting blood glucose， HbA1c， Homa-IS， systolic blood pressure are risk factors of type 2 diabetic nephropathy.

Objective To evaluate the cytotoxicity of high-osmolar contrast media (HOCM， diatrizoate) and low-osmolar contrast media(LOCM， iohexol) on human renal tubular epithelial cells(HKC)，and to determine the regulating roles of Bax/Bcl-2 and caspase-3 on apoptosis induced by contrast media (CM) in HKC. Methods HKC cells line was used. The subjects were divided into the following seven groups:HOCM group(111 mg iodine/ml)， HOCM group(74 mg iodine/ml)， LOCM group(111 mg iodine/ml)， LOCM group(iohexol iodine/ml)， mannitol high-osmolar control group， mannitol low-osmolar control group and culture media control group. The cytotoxicity of HOCM and LOCM was evaluated by MTT and LDH assay. Apoptosis was assessed by Hochest33258 fluorescence stained cytospins， TUNEL staining， DNA agarose gel electrophoresis， electron microscope and flow cytometric DNA analysis. The protein expression of Bax/Bcl-2 was examined by Western blot， and caspase-3 activity was determined by fluorometric method. Results Compared to the control group， LDH levels increased significantly(P < 0.05) and cell viability decreased in HOCM or LOCM group (P < 0.05) with an osmotic pressure and iodinated ion in a time-dependent manner. In HOCM groups， diatrizoate induced cultured HKC apoptosis. In LOCM groups， iohexol did not induced apoptosis. With mannitol under the same osmotic pressure， apoptosis increased in HKC incubated with diatrizoate(P<0.05). Bax， Bcl-2 production， and caspase-3 activity were upregulated in cultured HKC treated with 74 or 111 mg iodine/ml meglumine diatrizoate. Conclusions Both HOCM and LOCM have toxic effect on HKC cells. HOCM is more cytotoxic than LOCM. HOCM can induce cultured HKC cells apoptosis， which is related to the hypertonicity and iodine concentration of contrast media. Bax/Bcl-2 and caspase-3 may play an important role in mediating apoptosis in contrast media- induced cultured HKC.

Objective To investigate the therapeutic effects of Astragalus & Angelica (A&A)， the mixture of Chinese herbs， on different vasoconstrictors and vasodilators in the process of renal interstitial fibrosis in rats with unilateral ureteral obstruction (UUO). Methods Wistar rats were randomly divided into Sham，UUO and UAA (UUO+A&A) groups. After administration of A&A(14 g&#8226;kg^-1&#8226;d^-1) for 0， 3， 7 and 10 days， the levels of Ang-Ⅱ， ET-1， nitric oxide(NO) and the activities of different NOS in renal homogenate were measured by RIA or enzyme method. The expression levels of eNOS， nNOS， iNOS were detected in the kidney by immunohistochemistry and semi-quantitively assessed by Western blot. Results After A&A administration， the levels of Ang-Ⅱ and ET-I were increased in UUO at all time points (P < 0.05). A&A suppressed Ang-Ⅱ level only at day 3 (1.12±0.24 vs 1.80±0.19， P < 0.05) but not at the other days. It had no any effect on ET-1. On the other hand， NO release was increased at day 7 and day 10 in UUO rats (P < 0.05)， but it was elevated earlier at day 3 (P < 0.05) and was progressively increased in the following days in UAA group. In further study， the distribution of three isoforms of NOS in the kidney showed no difference between UUO and UAA groups. The activities of constitutive NOS and iNOS remained unchange in UUO group as compared to Sham. In contrast， the activity of constitutive NOS was much higher in UAA as compared to UUO rats， it was un-regulated by 78%， 68% and 78% at day 3， 7 and day 10 respectively， even though the protein expression levels of eNOS， nNOS and iNOS in renal tissue were unaffected in UAA rats. Conclusions The anti-fibrosis effects of A&A may be associated with improving chronic ischemic status in UUO rats. In the early stage of UUO， A&A down-regulates Ang-II and persistently enhances eNOS activities， which leads to up-regulation of NO production.

Objective To examine the hypothesis that the ameliorative effect of adrenalectomy on remnant nephropathy rats depends on low aldosterone level. Methods Male Wistar rats weighing 180~200 g were divided into the following 5 groups:SHAM rats，5/6 nephrectomy rats (SNX group)， nephrectomy and adrenalectomized rats (ADX group)， bi-ectomized rats infused with exogenous dexamethasone (DXM group) or plus aldosterone (ALDO group) by osmotic mini-pump at 12 μg&#8226;kg^-1&#8226;d^-1 and 40 μg&#8226;kg^-1&#8226;d^-1， respectively. They had free access to saline and were sacrificed at week 8. Results 5/6 rats had marked proteinuria，hypertension，glomerulosclerosis and up-regulated expression of TGF-β1 as high as > 4-fold elevation in renal cortex in plasma aldosterone as compared to those of the SHAM rats. The above pathologies were markedly improved in bi-ectomised rats with significantly lower aldosterone level. Being constantly infused exogenous aldosterone， bi-ectomized rats manifested greater proteinuria，hypertension，glomerulosclerosis and increased level of TGF-β1 compared to bi-ectomised rats. Indeed， these features were similar in exogenous aldosterone rats and 5/6 nephrectomized rats. Furthermore， the expression of mineralocorticoid receptor (MR) mRNA was remarkablely enhanced in SNX group and was decreased in ADX group. However， the mRNA expression of 11β-hydroxysteroid dehydrogenase Ⅱ (11β-HSD2) in each group was opposite to that of MRmRNA. Ccr and kidney/body weight showed no differences among four experimental groups. Conclusion Aldosterone contributes to the progression of ablative nephropathy in the rat through mechanisms other than systolic blood pressure.

Objective To explore the effect of Rhein on TGF-β1-induced renal interstitial fibroblast activation. Methods Normal rat renal interstitial fibroblast (NRK-49F) treated by TGF-β1 were cultured with or without Rhein at different concentrations. Cell number was counted， and cell cycle was analyzed by flow cytometry. The fibroblast activation was assessed by expression of α-smooth muscle actin (α-SMA)， and deposition of fibronectin (FN) by Western blotting. Results Rhein suppressed TGF-β-induced fibroblast growth in time-and dose-dependent manner， and blocked resting cells into S and G2/M phase. It was demonstrated that Rhein abolished α-SMA expression of fibroblast induced by TGF-β1 in a dose-dependent manner. Meanwhile， Rhein suppressed TGF-β1-induced FN deposition and its extracellular assembly in fibroblast. Conclusion Rhein can block renal interstitial fibroblast growth and activation， and the effect of Rhubarb on delaying progression of CRF may be associated with this action of Rhein.

Objective To study the effects of simvastatin on proliferation and apoptosis in rat mesangial cells in vitro， and to investigate the signal pathways involved in apoptosis induced by simvastatin. Methods Cultured mesangial cells were treated with simvastatin. Proliferation of mesangial cells was examined by MTT assay. Simvastatin-treated apoptotic mesangial cells were observed by electron microscopy. Propidium iodide(PI) staining and flow cytometry were employed for quantitative measurement of apoptosis. Caspase-3 activation was determined by CaspGLOW Green Caspase-3 Staining Kit. Results (1)Simvastatin significantly inhibited proliferation of mesangial cells compared with control(P<0.05). (2)Under electron microscopy， mesangial cells with condensed chromatin， shrunken plasma， marginated nuclear chromatin or apoptotic body were observed in simvastatin-treated mesangial cells. Quantitative analysis of apoptotic mesangial cells showed that simvastatin did induce an increased apoptosis rate of rat mesangial cells in a dose-dependent manner. (3)Caspase-3 expression was activated by simvastatin in a dose- and time-dependent manner. Conclusions Proliferation inhibition and apoptosis induction of mesangial cells are involved in the mechanisms of the cholesterol-independent effects of simvastatin on the renal protection. The latter may be induced by activation of caspase-3.

Objective To investigate the effects of peritoneal dialysis fluids(PDF) on connective tissue growth factor (CTGF) synthesis in rat peritoneal mesothelial cells(RPMCs). Methods Cultured RPMCs were stimulated by 1.5% Dextrose(LG)， 2.5% Dextrose(MG)， 4.25% Dextrose(HG)， and 7.5% Icodextrin(ICO) dialysate for 24 hours. Serum free DMEM was used as negative control(Control)， TGF-β1(2.5 ng/ml) as positive control(TGF-β1). The mRNA expression levels of CTGF， α-SMA， and collagen Ⅰ were measured by RT-PCR. CTGF， α-SMA， and collagen Ⅰ protein in cell layer， secreted CTGF protein in culture supernatant were detected by Western blot. Results The CTGF mRNA could be detected in all the groups. The CTGF mRNA in HG group was significantly higher than those of other PDF groups and control group(P < 0.05). MG and ICO could also up-regulate CTGF mRNA synthesis(P < 0.05). CTGF protein expression in cell layer could be detected in all groups. The major protein species was a 38 KD， and a minor species of 25 KD. Consistent with RT-PCR reslult， HG group showed the highest level of expression(P < 0.05). In cell culture supernatant， only the species of 38 KD CTGF could be detected. The tendency was consistent with the CTGF protein expression in the cell layer. The expression levels of mRNA and protein of collagen Ⅰ in HG and TGF-β1 group were obviously increased compared with other groups， the latter had no differences. However， no significant difference was found in α-SMA mRNA and protein expression among all the groups. Conclusions There is a low level of CTGF expression in cultured RPMCs， both in mRNA and protein. Exposure to PDF， especially hypertonic glucose solution， may increase CTGF synthesis in peritoneal mesothelial cells and contribute to chronic peritoneal membrane alterations. Icodextrin may be more biocompatible than hypertonic glucose solution.

Objective To apply a novel proteomic technology to analyze urinary cytokine profiles in patients with CKD. Methods Ten subjects including 7 CKD patients and 3 normal controls were enrolled in this study. Differential excretion of urinary cytokines was determined by human cytokines antibody array (Raybiotech Norcross GA). As compared to controls， a two-fold change in spot intensity was considered significant. Results A total of 15 cytokines varied significantly in urinary samples from patients with CKD， comparing with controls. It was shown that MCP-1， RANTES， TIMP-1，TNF-α， VEGF， E-selectin， Fas， ICAM-1， IL-2， MMP-2， TGF-β increased by two to five folds in CKD patients with normal renal function， while the excretion of MCP-1， RANTES， TIMP-1， TNF-α and VEGF was further increased with the declining of renal function. A decreasing excretion of urinary VCAM-1 and PDGF was found in patients with renal failure. Impressively， the urinary MMP-9 excretion was 492 folds increase in CKD patients with normal renal function and 198 folds increase in renal failure patients as compared to normal controls. Conclusion A significant change of urinary cytokine profiles in patients with CKD is firstly demonstrated as compared to normal controls by using a novel antibody array technology， which may provide important information regarding to the role of cytokines in the progression of CKD.